Automatic mail-slot alarm.



L. M. ROBINSON. AUTOMATIC MAIL SLOT ALARM. APPLICATION FILED DEO.11, 190B.

91 9,081 Patehted Apr. 20, 1909.

2 SHEETSSHEET 1.

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Uivrrnn sieATEg LEWIS M. ROBINSO- OF MATT EA WAN N EV. YOR h.

AUTOIVIA'IIO "MAIL-SLOT I'ALARBT.

Specification of Letters Patent.

Patented April 20, 1909.

To all whom it may concern:

Be it known that I, Lnwrs M. EoBiNsoN, a citizen of the United States, residing at Matteawan, in the county of Dutchess and State of New York, have invented new and useful Improvements in Automatic ldail Slot Alarms, of which the following is a specification.

This invention is an improved automatic mail slot alarm for use in buildings, on doors or mail receiving boxes or other like objects which have slots through which mail matter is passed, the object of my invention being to provide an improved alarm for use in connection with a mail slot so that when mail mat' ter is put through the slot by the postman, the said apparatus will close an electric circuit automatically and thereby sound an alarm.

The invention consists in the construction, combination and arrangement of devices hereinafter described and claimed.

In the accompanying drawings :Figure 1 is an elevation of an automatic mail slot alarm constructed in accordance with this invention. Fig. 2 is a sectional view of the same on the plane indicated by the line aa of Fig. 1. Fig. 3 is a similar view on the plane indicated by the line b?) of Fig. 1. Fig. 4 is a detail perspective view of the actuating arm. Fig. 5 is a similar view of the circuit closing operating arm.

A door, box or other device having a mail receiving slot A is indicated at B. Below the slot A is a stop 1, the flap or cover which closes the mail slot on the inner side of the door is indicated at 2 and is pivotally connected at its upper corners, as at 3, to a plate 1 which may be readily secured to the door or other object as by means of screws 5. The said plate is further provided with bearings 6 for a rock shaft 7. An arm 8 is secured to the said rock shaft as by means of a screw 9 and the free end of the said arm bears 011 the cover or flap 2 so that, when the latter is opened by the passage of mail matter through the mail slot, said arm 8 will be turned angularly and the rock shaft will also be caused to partially turn. An arm 10 which is shorter than the arm 8 is also secured to the rock shaft as by means of a screw 11. A spring 12 is employed which tends to turn the rock shaft in one direction and to keep the arm 8 in engagement with the lap or cover The said arm 10 is provided on its under side ith a notch .13.

An insulating plate 14 is secured on the plate 4 as by means of screws 15 and serves a brace for a binding post or wire connection 16 and also as a brace for a post 17 which has a guide slot 18. A spring circuit-closing wire 19 is secured at one end at the base of the post la, is electrically connected therewith and its free end operates in the guide slot 18 of the post 17 and also engages the notch 13 in the arm 10. m1 adjusting screw 20 is attached to and properly insulated from the post 17 and forms a connection for a wire or wires which constitutes portions of L4.- electric circuit including a suitable battery and an electric bell (not shown) being indicated at 21 in Fig. 1.. Normally, while the cover 2 is closed, the arm 10 serves to depress the free end of the circuit closing wire 19 so as to keep said wire out of contact with the screw connector 20 hence opening the circuit. i /hen mail matter is passed through the slot A it necessarily raises the cover or flap 2 and the latter, as herein before stated, causes the arms 8 and 10 to partially turn together with the rock shaft '7 against the tension of the spring 12 and this movement of the arm 10 permits the spring circuit closing wire 19 to come in contact with the screw connector 20, thus closing the circuit and causing the bell to be sounded. The flap or cover 2 normally closes by gravity and the spring 12 keeps the arm 18 normally in engagement with said cover or flap and causes the arm 10 to keep the circuit closer 19 out of contact with the connector screw 20.

It will be understood that the mail slot cover or flap together with all the other parts of my improved apparatus is secured to the plate 4 and hence the device may be readily installed on a door or other object or as readily removed therefrom when. desired.

What is claimed is 1. A mail slot alarm apparatus comprising a base plate having bearings, a mail slot closing cover or flap hingedly connected to said base plate, a rock shaft in said bearing having a rock arm and also having a device engaging said cover or flap and operated by the latter to turn said rock shaft when said flap is open, a spring to turn said rock shaft in the reverse direction, and a circuit closing 5 device including an element operated by said 1 rock arm.

2. A mail slot or alarm comprising a base plate having bearings, a rock shaft journaled in said bearings, a spring to turn said shaft in one direction, a pair of arms of unequal length attached to said rock shaft, a mail v slot cover or flap hingedly connected to said base plate engaged by the longer ofsaid arms 1 and normally maintained by said longer arm 1 in a closed position, and a circuit closing device including an element operated by the shorter arm and normally held by said j shorter arm in circuit opening position.

In testimony whereof I a'ffix my signature in presence of two Witnesses.

LEWIS M. ROBINSON.

YVitnesses SAMUEL B. MCDOWELL, WILLIAM R. MACKEN. 

